I took an in-flight photo of my PowerFLARM antenna installation (way
up in the nose of my DG-300). If you think the antenna obstructs too
much of your vision for safety, compare it to the yaw string! Glider
wings are much wider than either item, BTW - and I think you have a
better chance of seeing relative motion of the wings than picking out
the shape of a fuselage or vertical fin.

http://www.flickr.com/photos/noel_wade/7518094912/

For the record, my antenna sticks up slightly above my compass, and is
on a plastic arm that puts it 7" ahead of the compass so it has a
roughly 320-degree clear field-of-view. I can see targets 6-8 miles
away occasionally, and 4-6 miles away without any trouble - even at my
6 o'clock when the target is only 200 feet behind me, 100 feet below
me, and chasing my ass (ask me how I know!). The only time I lose lock
on sailplanes is when they're at least 2 miles away and thermalling
above my altitude. The target comes and goes; and I suspect that has
as more to do with their antenna and fuselage/internals than my
antenna.

My ADS-B antenna is mounted on the inside of my turtle-deck, and picks
up transponders at least 6 miles out.

I will admit that it took a solid day of work to install my PowerFLARM
and run all the wires and get all the cables working. There was
grumbling and cursing involved (mostly because I was having to mount
it under the seatpan as my DG-300 has no space left in the instrument
pedestal). However once I started flying with it, all was
forgiven. I flew with it in the Standard Class Nationals and I am
100% convinced that it was well worth the effort. I am VERY HAPPY I
have it. Because of the terrain and conditions, several tasks
included MATs with reciprocal headings - and on at least 2 or 3
occasions FLARM alerted me to head-on traffic near my altitude, flying
near cloudbase where I would NOT have seen the traffic until the last
moment.

I hope future generations of the product have a better form-factor and
become easier to install (or at least some enterprising distributor/
reseller starts offering custom wiring harnesses)... But the current
version is fine as it stands and offers a lot of value - and safety -
for the money!

--Noel
P.S. (OK, I _do_ wish they'd hurry up and get the logger
functionality working... I almost didn't have a valid flight trace at
the Nats and could have used a backup logger that's IGC-legal!)